2,312 research outputs found
Conversión de Oleum papaveris seminis en ésteres metílicos mediante un proceso de esterificación: Optimización y estudio cinético
This paper presents an acid pre-treatment process and a kinetic study for the esterification reaction of Oleum papaveris seminis oil with methanol in the presence of amberlite 120 as a solid catalyst to convert the oil into methyl esters. Response surface methodology (RSM) was applied to optimize the reaction parameters, i.e. reaction time, percentage of the catalyst and volume ratio of methanol to oil. The results revealed that 0.87% w/w of catalyst concentration and 44.70% v/v of methanol to oil ratio provided final free fatty acid (FFA) contents of 0.60% w/w at 102.40 min of reaction time. It proved that the contribution of Amberlite 120 in the esterification of FFA was highly significant. The kinetics of the esterification in Oleum papaveris seminis oil with methanol in the presence of the amberlite 120 catalyst were also investigated to establish the reaction rate constant (k), reaction order, and activation energy. The study was performed under the optimized parameters at three reaction temperatures (50, 55, and 60 ºC). The value of k was in the range of 0.013 to 0.027 min-1. The first-order kinetics’ model was suitable for this irreversible FFA esterification with the activation energy of about 60.9 KJ·mol-1.En este artículo se presenta un proceso de pre-tratamiento con ácido, y un estudio cinético de la reacción de esterificación. Se utiliza Oleum papaveris seminis con metanol en presencia de Amberlite 120 como catalizador sólido para la formación de los ésteres metílicos. Se aplicó una metodología de superficie de respuesta (RSM) para optimizar los parámetros de la reacción; es decir, tiempo de reacción, porcentaje de la relación de catalizador y volumen de metanol - aceite. Los resultados mostraron que el 0,87% w/w de la concentración de catalizador y 44,70% v/v de metanol en relación al aceite dan lugar a un contenido final de ácidos grasos libres (FFA) de 0,60% w/w en 102,40 min de tiempo de reacción. Se demostró que la contribución de Amberlite 120 en la esterificación de los FFA fue altamente significativa. La cinética de la esterificación del Oleum papaveris Seminis con metanol en presencia del catalizador Amberlite 120 también se investigó para establecer la constante de velocidad de reacción (k), orden de la reacción, y la energía de activación. El estudio se realizó bajo los parámetros optimizados a tres temperaturas de reacción (50, 55, y 60 °C). El valor de la constante k fué del rango de 0.013 a 0,027 min-1. El modelo de cinética de primer orden fue el adecuado para esta esterificación FFA irreversible con una energía de activación de aproximadamente 60,9 KJ mol -1
The impact of multi-enzyme fortification on growth performance, intestinal morphology, nutrient digestibility, and meat quality of broiler chickens fed a standard or low-density diet
This research aimed to study the impact of supplementation of three multi-enzyme levels (0, 0.1, and 0.2% of feed) and two levels of dietary treatments [standard diet (SD) and low-density diet (LDD)] on growth performance, carcass traits, digestibility, and meat quality of broilers from 1 to 38 days of age. A total of 216 1-day-old Arbor Acres broiler chicks were randomly assigned to a factorial experiment (2 × 3) comprising six dietary treatments, each with six replicates and each replicate with six chickens. The results showed that the LDD significantly reduced body weight gain by 5.0%, compared with the SD. Multi-enzymes significantly improved body weight gain and the production index (PI) relative to the SD. The feed conversion ratio was significantly enhanced with increased multi-enzymes from 1 to 21 days. A significant relation between the multi-enzyme concentration and type of dietary treatment was observed in body weight gain and feed conversion ratio from 1 to 21 days of age. Nitrogen-free extract digestibility was significantly increased by using the SD diet compared with using the LDD. Multi-enzyme supplementation improved the digestibility of dry matter, crude protein, crude fiber, and nitrogen-free extract in the LDD. A significant relationship was found between the multi-enzyme concentration and type of dietary treatment on the pancreas, liver, and intestinal length percentages. The meat dry matter concentration was significantly higher in the LDD group than in the SD group. The low-density diet significantly reduced the total revenue compared with the SD, whereas broilers fed the SD recorded significantly higher total revenue and economic efficiency than those fed the LDD. The low-density diet significantly increased economic efficiency compared with the SD. Multi-enzymes significantly increased the total revenue, net revenue, and economic efficiency than the standard set. In conclusion, using multi-enzymes in broiler diets improved body weight gain. The LDD with multi-enzymes showed enhanced body weight gain compared with the SD without multi-enzymes
2-[1-(2-Hydroxy-3-methoxybenzyl)-1H-benzimidazol-2-yl]-6-methoxyphenol methanol 1.13-solvate
In the main molecule of the title compound, C22H20N2O4·1.13CH4O, the dihedral angles between the benzimidazole plane and the two benzene rings are 80.53 (10) and 82.76 (10)°. The solvent molecules are disordered between three positions, with refined occupancies of 0.506 (13), 0.373 (13) and 0.249 (5). The crystal structure is stabilized by intermolecular O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds. The crystal studied was a merohedral twin [BASF ratio of 0.917 (1)/0.083 (1)]
2-Amino-N-(2-benzyloxy-3-methoxybenzylidene)aniline
The title compound, C21H20N2O2, a Schiff base ligand, contains two independent molecules (A and B) in the asymmetric unit, with similar conformations. In molecule A, the central benzene ring forms dihedral angles of 30.79 (13) and 23.56 (13)°, respectively, with the amino and benzyl benzene rings, while in molecule B these angles are 32.30 (13) and 13.13 (12)°. The molecular structure is stabilized by intramolecular N—H⋯N and C—H⋯O hydrogen bonds. The crystal structure is stabilized by N—H⋯N hydrogen bonds and N—H⋯π and C—H⋯π interactions
A Study of Organizational Justice on the Trust in Organization under the Mediating Role of Ethical Leadership
While previous sources of literature have proven the importance of justice, procedural, distributive and interactions are shown that have a greater impact on employees in the workplace. This paper summarizes the arguments and counterarguments within the scientific discussion on the issue of organizational justice as important predictors for many outcomes for individuals’ level and organization level
2-[1-(2-Hydroxy-3-methoxybenzyl)-1H-benzimidazol-2-yl]-6-methoxyphenol monohydrate
The asymmetric unit of the title compound, C22H20N2O4·H2O, comprises a substituted benzimidazole molecule and a water molecule of crystallization. The dihedral angles between the benzimidazole ring system and the two outer benzene rings are 16.54 (4) and 86.13 (4)°. The dihedral angle between the two hydroxy-substituted benzene rings is 82.20 (5)°. In the crystal structure, intermolecular O—H⋯O hydrogen bonds, involving the hydroxy groups and water molecules, form R
4
4(8) ring motifs, and link symmetry-related molecules into extended chains along the c axis. The crystal structure is further stabilized by weak intermolecular C—H⋯O hydrogen bonds, weak C—H⋯π and π–π stacking [centroid–centroid = 3.6495 (6)–3.7130 (6) Å] interactions. Intramolecular O—H⋯O and O—H⋯N interactions are also present
Gastrografin in the management of adhesive small bowel obstruction in children: a pilot study
Background/purpose Adhesive small bowel obstruction (ASBO) is a common emergency problem in children with previous abdominal surgery. Management protocols usually start with a conservative approach that may be successful in some cases, whereas in others it will end eventually by laparotomy with its associated morbidity and mortality. Our aim was to assess the role of water-soluble contrast, gastrografin, in the conservative management of ASBO. Patients and methods During the period January 2009 to July 2010, 33 patients with ASBO were presented at the Pediatric Surgery Unit at the Ain Shams University Hospitals. Patients who failed to improve after 48 h of conservative management in the absence of signs of strangulation were subjected to gastrografin administration. Patients were evaluated clinically and radiologically to determine the resolution of the adhesive attack, with estimation of hospital stay time. Results An oral administration of gastrografin successfully completed the conservative management in eight of 12 patients (66.6%), thus avoiding surgery and subsequently reducing hospital stay. Conclusion Gastrografin may have a valuable role in the management of ASBO, whether diagnostic or therapeutic, but a randomized controlled trial is needed to prove its effectiveness in reducing surgical intervention rate and hospital stay time.Keywords: adhesive, bowel obstruction, gastrografi
Synthesised Schiff Bases As A Potential Corrosion Inhibitor Of Aluminium.
The use of inhibitors for the protection against corrosion in acidic media such as nitric acid, sulfuric acid and
hydrochloric acid is widely reported. Schiff bases, a group of compounds containing nitrogen atoms were found to
be efficient inhibitors for corrosion in acidic media. Some research work revealed that the inhibition efficiency of
Schiff bases was found to be greater than their precursor, amines and aldehydes
Systems Immunology Analysis Reveals the Contribution of Pulmonary and Extrapulmonary Tissues to the Immunopathogenesis of Severe COVID-19 Patients
As one of the current global health conundrums, COVID-19 pandemic caused a dramatic increase of cases exceeding 79 million and 1.7 million deaths worldwide. Severe presentation of COVID-19 is characterized by cytokine storm and chronic inflammation resulting in multi-organ dysfunction. Currently, it is unclear whether extrapulmonary tissues contribute to the cytokine storm mediated-disease exacerbation. In this study, we applied systems immunology analysis to investigate the immunomodulatory effects of SARS-CoV-2 infection in lung, liver, kidney, and heart tissues and the potential contribution of these tissues to cytokines production. Notably, genes associated with neutrophil-mediated immune response (e.g. CXCL1) were particularly upregulated in lung, whereas genes associated with eosinophil-mediated immune response (e.g. CCL11) were particularly upregulated in heart tissue. In contrast, immune responses mediated by monocytes, dendritic cells, T-cells and B-cells were almost similarly dysregulated in all tissue types. Focused analysis of 14 cytokines classically upregulated in COVID-19 patients revealed that only some of these cytokines are dysregulated in lung tissue, whereas the other cytokines are upregulated in extrapulmonary tissues (e.g. IL6 and IL2RA). Investigations of potential mechanisms by which SARS-CoV-2 modulates the immune response and cytokine production revealed a marked dysregulation of NF-κB signaling particularly CBM complex and the NF-κB inhibitor BCL3. Moreover, overexpression of mucin family genes (e.g. MUC3A, MUC4, MUC5B, MUC16, and MUC17) and HSP90AB1 suggest that the exacerbated inflammation activated pulmonary and extrapulmonary tissues remodeling. In addition, we identified multiple sets of immune response associated genes upregulated in a tissue-specific manner (DCLRE1C, CHI3L1, and PARP14 in lung; APOA4, NFASC, WIPF3, and CD34 in liver; LILRA5, ISG20, S100A12, and HLX in kidney; and ASS1 and PTPN1 in heart). Altogether, these findings suggest that the cytokines storm triggered by SARS-CoV-2 infection is potentially the result of dysregulated cytokine production by inflamed pulmonary and extrapulmonary (e.g. liver, kidney, and heart) tissues
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